Turning off admonition graphics

I would like for admonition graphics to not be displayed in both HTML and PDF output. Based on the documentation, this seems to be a trivial thing to accomplish. I simply set the following in my customization layers:

<xsl:param name="admon.graphics" select="0"/>

And yet, the admonition graphics are still appearing in both HTML and FO output. Is this a bug in the 1.78.1 stylesheets? I actually thought the stylesheets were supposed to default to *not* displaying the admonition graphics?

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David Goss, Technical Writer
Frontier Science | www.fstrf.org

4033 Maple Rd, Amherst, NY 14226

(716) 834-0900 extension 7218